Apparatus for controlling heated stain removing digester baths



July 8, 1952 R. c. HEINEN 2,602,876

. APPARATUS FOR CONTROLLING HEATED STAIN REMOVING DIGESTER BATHS Filed Deo. 14, 1950 M ATTORNEY Patented July 8, .1952

UNITED slA'lEs. PATENTQFFICE APPARATUS FOR CONTROLLINGHEATED STAIN -REMOVING DIGESTER' BATHS Richard Carl Heinen, Dallas, Tex.` Application December 14, 1950, Serial No. 200,831

2 Claims.

, 1 i Thepresent invention `relates to an apparatus or unit especially suitablefor use by dry cleaners, launderers and garment dyers and kindred various enzyme preparations for the removal of' albuminous stains and blood from. wearing apparel sent to them for cleaning' or dyeing. So far as is known,v such stains cannot be removed readily from such Vgarmentsibyany other method. The enzyme preparations are well known to the trade.

The customary manner for the application of.

these enzyme` preparations Vis to clissolvea` certain amount of the powderedproduct in warm water and immerse the stained-fabric in the bath fora length of time necessary for the enzymeto convert the stain into watery soluble matter which is then ilushed out of the fabric. It has also long been known that these enzyme solutions are active only vso long as the bath in which they are contained is kept warm.` It is also a fact that, if:

the enzyme bath is too hot, the enzymes are 'clestroyed and also that, if the bathbecomes too cool, it becomes inactive. In general,` the activity` of all theenzyrnes is aiieeted by concentration, time, temperature and hydrogen-'ion concentrationA or pH. One of they most important factors is that of temperature. However, my invention relates to apparatus rather than to' methods.

Up until the present time the tradehas had no means or apparatus for properly maintaining the temperature of the enzyme bath; commonly calledfdigester bath. Usually the bath isr prepared in a pan or similar vesel and the bath is started out at the desired temperature but there has been no way to maintain that temperature. Consequently, the baths have cooled rapidly and have quickly become inefficient and ineiective. If a bath'is reheated Withdirect steamer any other method ofv direct heating, the enzymesare destroyed.

A principal object of this invention is to provide an improved digester apparatus or unit for use lin dry cleaning, laundering and garment dyeing establishments, or the like, -to removeldigestible spots by means of enzyme preparations 2 Y more efficiently and effectively thanhas been possible with apparatus heretofore .employed for the purpose; and to provide a digester apparatus or unit of thecharacter described whichV is highly practical, efcient and economical in use, and can operate to remove many stains heretofore considered to be unremovable.

Another object of this invention is to provide a digester unitorapparatus of the character described and one which will properly heat thehenzyme baths or othersolutions contained in such unit to the optimum temperature and then maine` tain such baths or solutions at the exact temperature pre-selected by the operator as-being the best temperature Vfor `the `particular .material and stains being treated.

A further object of this Yinvention is to provide a digester apparatus or unit oi the character described and one which is simple, sturdy and dur--v able in construction easily chargedv withl and emptied of the iiuids used, either in whole or in part. It is, therefore, ideal for continuedoperations, being simple to operate and to clean.t

To commence operations initially requiresonly the screwing .of the heating unit into theange, and iilling with water. The operation itself requires no'manipulation or adjustment of screws, bolts,.catches or other fastening means, Operation of the apparatus or unit hereafter requires onlythe changing of the solution and turning-on of electrical. current.y l p i Other. objects of this invention will VVbe inv part obvious and inl part pointed out hereinafter.

In accordance with this invention I provide a tank'adapted; to. hold. water, the itank beingA equipped with a thermostatically controlled heatf ing unit which becomes covered by Water in the tank, the thermostatic control 4of the heating unit being regulatable so that theheatingelement will heat the water in the tank to any .tem` perature within its 'range and pre-selectedby theA operator. Immersed in the water in the tank are the lower portions of one or more vatswhich are adapted to containrfiuid enzyme bath or other solution, the immersed portions of the vats be ing of heat conducting material so that the heat fromthewater .in the tank will be transmitted through the Walls of the vats and will heat the uid enzyme or lother solutions therein. By properly setting Vthe thermostatic control of the heating unit the water in .the tank and the fluid enzyme. baths or other solutions` in the vats are maintained kat a substantially constant temper-5 ature almost indeiinitely. It will bey noted that the direct heat is applied to the liquid in thetank the vat drain pipes pass through the bottom of the tank.

The invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be'more clearly set forth hereinafter and the scope of the application of which will be set forth in the claims that follow.

In order that a clearer understanding of this invention may be had attention is hereby directed to the accompanying drawing forming a part of thisapplication and illustrating certain possible embodiments of the invention and in which;

Figure 1 is a top plan view of a digester unit embodying this invention;

Figure 2 is a section view thereof and is taken on the line 2-2 of Figure l, and

Figure 3 is a sectional view thereof and is taken on the line 3-3 of Figure 1.

Similar reference characters refer to similar parts throughout the several views of the drawings.

The digester unit includes a tank Il) of suitable material, such as sheet metal, adapted to contain water. At one side of the tank is a funnellike member II open at the top and toward its lower end communicates with the interior of the tank through an aperture I2 in the side of the tank. This provides a visible tell-tale showing the water level in the tank and also provides an opening for filling the tank section of the apparatus or unit.

The bottom of the tank has a drain opening I3 closedrby a removable nipple I4.

Mounted on the front wall I()a of the tank and in an aperture therein is a heating unit having a heating element I5 and a thermo-responsive element I6 both within the tank and positioned to be immersed in water contained in the tank. An electrical control I1 for controlling the temperature of the heating element I5 in response to the call of the thermo-responsive element I6 is mounted on the outside of the tank and operatively associated with the heating element I5 and the thermo-responsive element I6. This heating unit and its control may be of any standard or conventional type such as is available on the market and no details of the unit need be given here.

. The tank I0 is provided with a cover Ill'1 having in the particular embodiment shown in the drawings two circular holes or apertures. There are also-shown two vats 20, each of circular shape and each having a bowl-like bottom portion 20a and an annular bead 2l extending around and outwardly of the vat approximately at the top of the bowl portion 20a. Each vat is adapted to be inserted into one of the openings in the cover Ib of the tank with the bead 2I resting on theltop Illb of the tank about said opening. When so positioned and supported each vat will have its lower bowl-shape portion 2liEL extended downwardly into the` tank I0 and immersed in the water in the tank. The bottom of each vat 20 has a drain opening 22 from which a drain tube 23 leads through a hole provided therefor in the bottom wall III# of the tank. The drain tube 23 of each vat is closed by a removable rubber cork 24 so that by removing the cork 24 the vat can be drained. Drain tubes 23 have their lower ends threaded, as at 23a, for extension of drain fa cilities whenever necessary. Vats 20 are aixed to tank I0 at top wall IIIb by soldering or welding angularbead 2| to said top Wall IDb and by soldering or welding the drain tubes 23 to bottom wall Illc of the tank at point through which drain tubes 23 extend through bottom wall of tank IUC. Thus making tank Il] liquid tight at all points except at tell-tale funnel II and drain opening I3 when drain-opening plug I4 is removed.

In operation the tank I0 is filled with water to its top and it will be noted that when so filled the water will be visible in the tell-tale funnel I I. The digester solution is then introduced into the vat or vats 20. The thermostat of the heating unit is set to heat the water in the tank and thereby the -enzyme solution in the vats to the optimum temperature for the particular fabric and stains to be treated and then the stained fabric is introduced therein and treated for the proper period of time. The temperature of the enzyme solutions in the vats will reach the optimum temperature selected. The height of the water in the tell-tale funnel II will indicate when the water in the tank requires replenishing and this can be done very easily by merely pouring water into the funnel I'I until the Water in the tank has been restored to the desired level. Any vat may be quickly and easily drained of enzyme solution, which may have become worn out, for replacement by another enzyme solution, by merely removing the rubber cork from the drain outlet of the vat, allowing the solution to empty from the vat, replacing the cork and putting the new solution into the vat.

For convenience of operation the tank I0 may be placed on anysuitable table or support, indicated by dot-and-dash lines at T inv Figures 2 and '3, the table having an open top so as not'to interfere with the drain tubes 23 of the vats 2U or the drain I3, I4 of the tank I0.

It will be apparent from the above that with my digester unit, by properly setting the heating unit, the enzyme solutions in the vats can be maintained for an indefinite length of time at the range of temperatures (i. e., between F. and 130 F.) at which said enzymes are active for the purpose intended and, particularly, at a preeselected temperature desired by the operator as the optimum temperature for the particular material and stains being treated. These enzymes in stain removing solutions are killed or Adestroyed at a temperature above 130 F. and are most effective at temperatures between F. and 'F. The temperature can be easily raised'or lowered by merely adjusting the thermostatic control of the heating unit accordingly. The heating unit will maintain an adjusted temperature substantially constant (i. e., within a degree or two, plus or minus) for an indefinite period-of time provided, of course, that an adequate supply of water be maintained inthe tank'. It is also noted that the apparatus or unit may be flushed and cleaned very easily without requiring the manipulation or unfastening of bolts, screws, catches, or the like, except that in flushing tank I0 it is desirable to unscrew the heating unit I1 from the tank I0 when it is desired to remove the heating unit therefrom.

As many changes may be made in the above construction without departing from the scope of the invention it is understood that all matter contained in the above description or shown in the accompanying drawing be illustrated and ,not in a limited sense.

bottom walls closed except for an opening in one side wall thereof and extending for a distance below the top of the tank, a lip extending upwardly and outwardly from said wall of the tank and from below said opening to approximately the top of the tank to form a tell-tale funnel,

at least two open-top digester-bath vats arranged in adjacent relation with one another and having their upper portion extending for a distance above the top of said tank and havingr their lower portions bowl-shaped and extending downwardly into the tank for the major portion of the depth of the tank but spaced from the bottom wall of the tank, a drain means for said tank, a drain duct extending downwardly `from each vat, respectively, to discharge exteriorly of the tank, an opening and closing means for said drain means and said drain ducts, said vats be ing supported by the tank and closing the top wall of said tank and being of heat conducting material, an electric immersion heating means to heat the water in said tank and projecting into the tank from and supported by a side wall of the tank and lying between said lower portions of said vats and adapted to be submerged in the water in the tank, and a regulatable thermostatic device mounted on the apparatus and controllably connected to said heating means and having the thermo-responsive means thereof disposed to be immersed into the water in said tank and between said vats, thereby the 'i proper and accurate temperature of enzyme digester baths or other solutions in said vats may be controlled and maintained for the essential optimum results from the solutions used in the vats.

2. An apparatus or unit useful for proper heating of and accurate temperature control of enzyme digester baths employed in the removal of stains from fabrics, said apparatus consisting of a relatively flat tank adapted to contain water and to be supported on a table-like support, at least two open-top digester-bath vats arranged in adjacent relation with one another and having their upper portion extending for a distance above the top of said tank and having their lower portions bowl-shaped and extending downwardly into the tank for the major portion of the depth of the tank but spaced from the bottom wall of the tank, a drain means for said tank, a drain duct extending downwardly from each vat, respectively, to discharge exteriorly of the tank, an opening and closing means for said drain means and said drain ducts, said vats being supported by the tank and closing the top wall of said tank and being of heat conducting material, an electric immersion heating means to heat the water in said tank and projecting into the tank from and supported by a side wall of the tank and lying between said lower portions of said vats and adapted to be submerged in the tank, and a regulatable thermostatic device mounted on the apparatus and controllably connected to said heating means and having the thermo-responsive means thereof disposed to be immersed into the water in said tank and between said vats, thereby the proper and accurate temperature of enzyme digester baths or other solutions in said vats may be controlled and maintained for the essential optimum results from the solutions used in the vats.

RICHARD CARL HEINEN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,695,008 Christensen Dec. 11, 1928 '2,164,282 Morris June 27, 1939 2,236,837 Rimmel Apr. 1, 1941 2,396,578 Kittel et al Mar. l2, 1946 

